A frequency hopping system involves carrier-frequency shifting in discrete increments in a sequence which determines the order of frequency usage. This permits a plurality of channels to share the same bandwidth without interference. According to the frequency-hopping technique, a plurality of frequencies is selected within the frequency band of interest and each channel hops rapidly from one frequency to the next according to a predetermined sequence. For example, in the 902-928 MHz band the FCC (i.e. United States Federal Communications Commission) requires at least fifty frequencies. In the 2400-2483.5 MHz frequency band, the FCC requires at least seventy-five frequencies. The frequency-hopping technique is especially useful for improving spectrum efficiency in mobile communications systems.
It is an object of the invention to use Galois Field theory to define the frequency hopping sequences for a plurality of channels in a communications system using the frequency-hopping technique.